Malibu V6-3.5L VIN 8 (2004)
-
May reflect off the ionosphere-skip
The AM frequencies have longer range due to the ground wave. The ground wave follows the curvature of the earth and is affected by its conductivity.
Greater conductivity equates to less signal loss thus transmission over water is better than over land. The AM band has a range of 80-320 km (50-200
miles).
FM Reception
The shorter wavelengths of the higher frequency FM band:
-
Reflect off obstacles
-
Are absorbed by the ground
-
Penetrate the ionosphere
Broadcasts in the FM band are limited to "line of sight" reception which is typically 40 km (25 miles). Even when out of a direct line of sight, the
signal may be reflected into areas that would be in a "shadow" otherwise. Factors which affect the line of sight include:
-
Height of the broadcast antenna
-
Height of the receiving antenna
-
Terrain and buildings in the broadcast path
Antenna System
The radio receiver uses an antenna to receive transmitted radio signals from a radio broadcast station. After the radio signal is received by the radio, it
undergoes further processing by the radio tuner. There are two types of antenna systems available on this vehicle. The antenna system (RPO U77) on
the sedan model is comprised of a very thin metal grid which is permanently affixed to the rear glass. A radio antenna module connects to the antenna
via a coax cable. On the extended model a fixed mast antenna (RPO U71) is used.
Theft Deterrent
The Theftlock theft deterrent system is a feature on all base and uplevel radios. The theft deterrent system utilizes GMLAN serial data to determine if
the radio is in the appropriate vehicle. Each time the radio receives the vehicle ID (VIN) packet message and is in the RUN power mode, it compares
the VIN information it has stored to the received VIN packet message containing VIN information. The radio receives this message from a module on
the GMLAN serial data circuit responsible for transmitting that information. If a mis-match occurs, the radio display will indicate to the user the radio
is locked. Once this takes place, the radio will not respond to any button presses and become inoperative. The 2 scenarios able to cause this condition
are:
-
A radio is installed from another vehicle.
-
A module which communicates on the GMLAN serial data circuit which supplies VIN information to the radio is replaced and not properly setup
with the correct VIN information for that vehicle.
The only way to unlock the radio is by using a scan tool. The scan tool sends the appropriate diagnostic message (relearn VIN) to reset the radio.
Using a scan tool, select the radio VIN relearn procedure from the module replacement screen in Vehicle Control Systems.
Integral 6 Disc CD Changer (ICDX [Uplevel])
The Integral Multi Disc CD Changer has the capability of storing and playing up to 6 compact discs. The Integral Multi Disc CD Changer has a
shock-absorbing system. Only under extreme operating temperatures or severe shock or vibration should the compact disc player skip or mute. If the
customer travels an abnormally rough road, a skip condition may be normal. Test drive the vehicle on a normal road with a known good CD. If the
condition is still present, replace the radio.
The use of CD lens cleaner discs is not advised, due to the risk of contaminating the lens of the CD optics with lubricants internal to the CD
mechanism.
IMPORTANT: The CD mechanism within the ICDX radio will begin an initialization routine after a battery connect (e.g., connecting radio
connector C1). The initialization process takes approximately 25 seconds to complete. It is very critical that the initialization is completed before
removing battery power from the radio, in order for the complex moving parts of the CD mechanism to be positioned properly before shipping and/or
handling purposes. Damage may result to the moving parts of the CD mechanism if battery power is removed during the initialization routine. The
damage occurs to the CD mechanism during subsequent shipping or handling operations. The extent of the damage causes the CD mechanism not to
recover and the mechanism becomes inoperative.
Single Disc Loading
To operate the Integral Multi Disc CD Changer in the single play mode, press and release the LOAD button within 2 seconds. The radio display
indicates to wait before inserting a CD. The CD mechanism will move the lowest numbered empty slot into position and then produce an audible beep.
Load a disc when the radio display indicates to insert a CD. If the radio is ON, the disc will begin to play automatically. If the radio is OFF, press the
LOAD button for the disc to play.
Multi Disc Loading
To operate the Multi Disc CD Changer in the multi disc mode, press and hold the LOAD button for more than two seconds. An audible beep will be
heard and the radio displays the message ALL CDs then an indication to wait before inserting a CD. The CD mechanism will move the lowest
numbered empty slot into position and then produce an audible beep. The radio will then display a message to insert a CD. After inserting a CD the
radio produces an audible beep. The radio displays another message indicating to wait before inserting a CD. Insert another CD when the display
indicates inserting one. Repeat this procedure to continue loading the remaining discs. The CD changer holds up to six discs.
